Charlie Culberson

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The Giants selected Culberson in the supplemental first round of the 2007 draft.

The 23-year-old Georgian isn't in the big leagues because of anything special that he did in the minor leagues. His minor league strikeout-to-walk ratios suggest that he doesn't control the strike zone well and that he will expand the zone. He follows the hitting philosophy of so many current Giants: swing in case it's a strike and swing hard in case you hit it.

However, his hot start in Triple A Fresno gave the Giants hope that he can give them more than the one extra base hit that Ryan Theriot and Manny Burriss have combined for this season.

His minor league track record does not suggest that Culberson is a player that is going to be the long-term answer at second base. However, Culberson has some power and speed to go with the pedigree of being a first-round draft choice.

Some prospects bloom later than others, and the Giants did the right thing by calling him up now so they can determine if he is going to be a late bloomer.

Joe Panik

From MLB.com

Panik, the Giants first-round draft choice last season out of St. John's University, tore up low-A ball and the Arizona Fall League last season before struggling upon his promotion to high-A ball this year.

Unlike Culberson, Panik's strength is his ability to control the strike zone. He walks quite a bit while hardly striking out. His contact-oriented approach does not yield to a lot of power, however.

The Giants are currently using Panik as a shortstop in San Jose, but he can also play second base. The 21-year-old could be a long-term solution at either position, but he likely needs at least two more full seasons in the minor leagues given his early struggles so far this season.

While Culberson might be a solution in the short term as well as in the long term, Panik is somebody that Giants fans are going to have to wait a while for.

Kelly Johnson

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The Toronto Blue Jays' current second baseman, Kelly Johnson, will be a free agent at the end of the season. If the Blue Jays fall out of contention before the trading deadline, the Giants could make a move for him during the season. If not, he could be a free-agent target during the offseason.

At 30 years old, Johnson is an average defensive player with above average power and patience for the position. The Giants were linked to him at the trading deadline during the 2010 season, so there is a prior history of interest with him.

The biggest weakness to his game is his propensity for the strikeout. His contact problems have caused him to alternate outstanding seasons with average ones during his seven-year career.

His power and patience would be a welcome addition to a position that is currently sorely lacking in on-base and slugging percentage. He is never going to hit .300 like Freddy Sanchez, but at least Johnson is durable enough to stay on the field.

Starlin Castro

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The Chicago Cubs 22-year-old shortstop is five years away from free agency, so it would take a blockbuster trade to bring him to San Francisco.

The Cubs are in rebuilding mode, so they aren't likely to move one of their few young, valuable assets. However, with Theo Epstein and Jed Hoyer taking over the front office this offseason, they could determine that Castro has more value to the franchise as a trade chip than as the best player on a team that's going nowhere.

Castro fits the mold of the offensive player the Giants covet: he doesn't walk very often, he hardly strikes out and he can hit .300 in his sleep. He reminds me of Pablo Sandoval at the plate with more speed and less power.

It may be a pipe dream for the Giants to acquire Castro, but if the Cubs make him available, they would be getting an All-Star caliber player who is only going to get better.

Alberto Callaspo

Unlike Castro, Alberto Callaspo is likely to be available in a trade. He lost his starting job at third base to Mark Trumbo and is buried behind Howie Kendrick at second base for the Angels.

29-year-old Callaspo has good plate discipline and contact skills. He can hit for average, get on base and hit for gap power.

He would certainly be an upgrade over what the Giants are currently running out at second base even though his best position defensively is third base.

If Kelly Johnson does not become available in a trade and if Charlie Culberson does not prove to be the answer, the Giants should make a run at Callaspo to fill the void at second base for the next few seasons.

J.J. Hardy

J.J. Hardy hits a lot of home runs while playing excellent defense at shortstop, two skills that make him a valuable commodity.

The 29-year-old shortstop signed a three-year contract extension last season making it unlikely that the Orioles would suddenly trade him—especially after their hot start to the 2012 season.

However, the Orioles have had hot starts in past seasons only to end up in the cellar of the American League East, which is where they are likely to end up by the trade deadline. Their top prospect, Manny Machado, plays shortstop as well, so the Orioles would be dealing from a position of strength.

If the Orioles do become inclined to move Hardy, the Giants would be getting an upgrade on both sides of the ball. Hardy is more sure-handed than Crawford in the field while also providing 25 home runs at the bottom of the lineup.

Elvis Andrus

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Like Hardy, Andrus recently signed a three-year contract extension, but the Texas Rangers also have a prospect knocking at the door in Double-A named Jurickson Profar. If the Rangers decide to deal Andrus to make room for Profar, the Giants could deal for one of the best young shortstops in the game.

23-year-old Andrus is an elite defensive player and baserunner. He has excellent contact skills and plate discipline with power that is improving each season.

Andrus has improved drastically since his rookie season four years ago. Given his youth, he is an excellent bet to become a perennial All-Star. If Andrus becomes available in a trade when Profar is ready for the show, the Giants could fill their shortstop void for the next decade.

Alexei Ramirez

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The Chicago White Sox began a partial rebuilding plan this offseason. They have played fairly well to start the season in the weak American League Central which likely will put the rebuild on hold for now.

However, if the White Sox fall out of contention before the trade deadline, Alexei Ramirez would be one of their best trade chips.

Ramirez, 30, is an outstanding defensive shortstop with 15-20 home run power and excellent speed—three ingredients currently missing from the middle of the Giants infield.

Ramirez also signed a team-friendly four-year contract extension last season making him a potential bargain if the White Sox decide to deal him.

Robinson Cano

However, the new Collective Bargaining Agreement (CBA) has made it tougher for the Yankees to sign Cano to a long-term deal past 2013. The new CBA imposes much stiffer penalties on rich teams like the Yankees for exceeding Major League Baseball's luxury tax threshold. The Yankees will need to cut payroll to get below the luxury tax level unless they want to pay the new, harsher penalties.

If the Yankees cannot afford to keep Cano after 2013, the Giants could make a run at the best second baseman in the game. Cano plays the game effortlessly, gliding around second base with excellent range while swinging with a sweet, smooth left-handed swing. He is a five-tool player, something the Giants have not had since the prime of Barry Bonds' career.

The Yankees will do everything they can to keep Cano, but the new CBA could limit their ability to keep him. If Cano becomes a free agent, the Giants could make a run at one of the best players in the sport.

Macier Izturis

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Macier Izturis has always been good enough to be an everyday player, but has never had the opportunity to flourish with the Angels. He will get that opportunity next season when he hits free agency for the first time.

Izturis can play either middle infield spot adequately while providing speed, contact, a decent batting average, a good on-base percentage and enough power to hit doubles consistently. He would not generate the hype of someone like Starlin Castro, Elvis Andrus or Robinson Cano, but he would be an upgrade at either middle infield position.

Unlike Castro, Andrus and Cano, Izturis is going to be freely available next offseason. If the Giants are unable to acquire anyone else, Izturis would be a nice fallback option. He isn't the type of player that is going to sell seats, but he can make Giants fans forget the putrid performances of Manny Burriss and Brandon Crawford.